Problem Transitioning from Excel to Power BI ... Using Parameters

Scenario:

I have built a model Using Power Pivot 2016 whereby I can have different source data inputs for an unlimited number of clients.

Client data is stored in discrete Excel Workbooks which are stored in a Client Folder.

I have created a Power Query that reads the contents of this folder and returns the contents to a Worksheet Table ... very straightforward stuff.


Using Ken Puls' fnGetParameter structure, I then reference the contents of this table by putting a Data Validation Rule in the Value column of the Parameters table,

This all works fine in Excel.

I now want to migrate the Application to Power BI Desktop and am having difficulty in utilising the new Get Parameters from a Query Option as announced in the July Update.

My thinking is that I should be able to create a Power Query that will read the contents of the folder that holds the Client Workbooks and all me to make a selection from the list.
I want to store this selection as a Parameter that I can reference in the other queries in the pbix file (there are up to 60 individual queries in the App at this stage).

When defining the Parameter I am unable to the Client List Query to display the contents ... so that I can make the selection once at run time.

I am not sure if I have given enough details here to get across what my problem is ... if not please let me know.

Thanks,

Ted

Problem Resolved!!

The Query that is referenced in the Allowed Values field when defining a Parameter must be returning a List.

In my case I was trying to pass a Table to the Parameter set-up.

Apologies for the Double Thread entry.